Vacuum tubes were used in early computers.
Trainsistors replaced vacuum tubes starting in 1956,by the mid-1960s transistors were replaced by
intergrated circuits.
*Computers in Perspective :
Integrated circuits brought:
-Increased reliability
-Smaller size
-Higher speed
-Higher efficiency
-Lower cost
1971:The first microprocessor was invented by Intel engineers.
The personal computer revolution began in 1970:
-Apple
-Commodore
-Tandy
*Personal Computers:
#PCs serve a single user at a time.
~ Common applications include:
-word processing
-accounting
-gaming
-enjoying digital music and video
*Portable Computers:machines that ar not tied to the desktop
-Notebook (laptops)
-Handheld computers (PDAs)
*Basic Functions of a Computer
Receive input: Accept information from the outside world
Process information: Perform arithmetic or logical (decision-making) operations on information
Produce output: Communicate information to the outside world
Store information: Move and store information in memory.
*Basic Components of a Computer :
-Input devices
Keyboards and pointing devices(mouse)
-Output devices
Display or video monitor
Printer
Speakers
-Central Processing Unit (CPU)
A bit about Bits :
Bits,Bytes,and Buzzwords
Byte = 8 bits
Kilobyte (KB) = 1 Thousand Bytes
Megabytes (MB) = 1 Million Bytes
Gigabytes (GB) = 1 Billion Bytes
Terabytes (TB) = 1 Trillion Bytes
-ROM (read-only memory)
Information stored permanently on a chip
Contains startup instructions and other permanent data
-CMOS (complementary metal oxide)
semiconductor)
Special low-energy kind of RAM
-Flash memory
Used for phones, pagers, portable computers, handheld computers, and PDAs
Ø Standard keyboard
Ø Ergonomic keyboards
q To address possible medical problems
Ø Wireless keyboard
Ø Folding keyboards
q Used with palm-sized computers
Ø One-handed keyboards
Ø Keyboards printed on membranes
-Monitor size: Measured as a diagonal line across the screen
-Resolution: The number of pixels displayed on the screen
-Pixels (or picture elements): tiny dots that compose a picture
-The higher the resolution, the closer together the dots.
-Image quality is affected by resolution and color depth (or bit depth).
-Color depth refers to the number of different colors a monitor displays at one time.
Hardware and Software platforms:
-Windows Vista -Mac OS X(10)
-Windows Server 2003 -Mac OS 9
-Windows XP -Linux,Son solaris,and other UNIX varations
-Windows ME
-Microsoft Windows CE
-Working with a word processor involves several steps:Wordsmith's Toolbox:
-Entering text
-Editing text
-Formatting the document
-Proofreading the document
-Saving the document on disk
-Printing the document
Rules of Thumb: Avoiding Spreadsheet Pitfalls
-Plan the worksheet before you start entering values and formulas.
-Make your assumptions as accurate as possible.
-Double-check every formula and value.
-Make formulas readable.
-Check your output against other systems.
-Build in cross-checks.
-Change the input data values and study the results.
-Take advantage of pre-programmed functions, templates, and macros..
-Use a spreadsheet as a decision-making aid, not as a decision-maker.
-Even though the computer was designed to work with numbers, it can be an
important tool for working with words as well.
-Word processing software enables you to use commands to edit text on screen,
without having to retype messages.
-Outlining software, spell checkers, and online references can be very helpful.
-Desktop publishing produces professional-quality text-and-graphics documents.
-Spreadsheets can be used for tracking, calculating, forecasting, and almost any
other task that involves repetitive numeric calculations. Most spreadsheet programs
have charting capabilities.
-Specialized software allows you to perform accounting tasks, tax preparation, and a
variety of business functions without the aid of spreadsheets.
-Symbolic mathematic and statistical-analysis software can help present data in
meaningful ways.
-Scientific visualization software can help us understand relationships that are
invisible to the naked eye.
-Computer modeling and simulation can be powerful tools for understanding the
world and making better decisions
Computer Graphics :
Pixels: tiny dots of white, black, or color that make up images on the screen
Palette of tools mimics real-world painting tools
-Also contains other tools that are unique to computers
Bitmapped graphics (or raster graphics): pictures that show how the pixels are mapped on the screen
Color depth: the number of bits devoted to each pixel
Resolution: the density of the pixels
Making Powerful Presentations:
-Remember your goal..
-Remember your audience.
-Outline your ideas.
-Be stingy with words.
-Keep it simple.
-Use a consistent design.
-Be smart with art.
-Keep each slide focused.
-Tell them what you’re going to tell them, then tell them, then tell them what you told them.
What Good Is a Database?
*A database:
-A collection of information stored on computer disks
*Database software:
-Application software
(like word processing and spreadsheet software)
*Designed to maintain databases
(collections of information)
Database Operations:
-Import: receive data in the form of text files
-Browse: navigate through information
-Query: find records that match specific criteria
*Personal information manager (PIM): an electronic organizer
*Automates some or all of the following functions:
-Address/phone book
-Appointment calendar
-To-do list
-Miscellaneous notes
*Handheld computers can share information with applications such as iCalendar running on PCs and Macintoshes.
*From File Managers to Database Management Systems
-File manager: enables users to work with one file at a time
-Database management system (DBMS): manipulates data in a large collection of files, cross-referencing between files as needed
*Database Trends:
-Batch processing: users accumulate transactions and input them into the computer
in large batches
Real-Time computing: allows instant access to information
-Interactive processing: has replaced batch processing for most applications
-Users can now interact with data through terminals, viewing and changing values
online in real-time.
-Batch processing is still used for jobs in which it makes sense to do a lot of
transactions at once.
*Rules of Thumb: Dealing with Databases
-Choose the right tool for the job.
-Think about how you’ll get the information out before you put it in.
-Start with a plan, and be prepared to change your plan.
-Make your data consistent; inconsistencies can mess up sorting and make searching difficult.
-Databases are only as good as their data.
-Query with care.
-If at first you don’t succeed, try another approach.
#Big Brother and Big Business
*Other information technologies amplify the threat to personal privacy:
*Networks make it possible for personal data to be transmitted almost anywhere instantly.
*Microsoft’s Passport, part of its .NET technologies, can optionally collect the following information in a central database controlled by Microsoft:
-Passwords
-Credit card numbers
-Other consumer information
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